The Athabascan dialects of California fall into four groups: the Tolowa, which is connected with the Oregonian tongues of Chetco and Rogue Rivers; The Hupa group; the small and undiversified Mattole, whose distinctness is not readily explainable either by the topography of their habitat or by a juxtaposition to alien neighbors, and therefore indicates the operation of an unknown historical factor — unless Mattole shall prove to be a subdivision of Hupa; and the Southern or Kineste or Kuneste or Wailaki group, the most widely spread of the four.

For the sake of exactness a fifth group might be added, that of the Rogue River people, to whom a narrow strip along the northern edge of the State, in contact with the Shasta, and another adjacent to the Tolowa, have been assigned on the map.
Both these belts are only a few miles wide and high up in the mountains.
They may have been visited and hunted in; they were certainly not settled.
They represent a little marginal fringe which nominally laps into the present consideration only because the artificial State lines that set a boundary to this study do not coincide exactly with the barriers set by nature.

The Athabascans were a hill people, and most of them inhabited their permanent homes by the side of rivers only during a part of each year.
But their territories coincide almost as exactly with stream drainages as if a systematist had planned their di[s]tribution.
This relation appears in the following tabulation:

Tolowa group

Smith River drainage.

Hupa group

Trinity-Redwood-Mad drainage.

Hupa

Lower Trinity River.

Chilula

Lower Redwood Creek.

Whilkut

Mad River (and upper Redwood drainage).

Mattole group (Distinctness doubtful.)

Mattole and Bear River drainages (and a short stretch of Lower Eel River).

Southern group

All Eel River drainage from the first forks up, except for the headwaters which were Yuki.